1. Field of the Invention
The invention is directed to an improved high-pressure pump, in particular for a fuel injection device of an internal combustion engine.
2. Description of the Prior Art
One high-pressure pump for a fuel injection device of an internal combustion engine, known from German Patent Disclosure DE 198 44 326 A1, has a plurality of pump elements, which each have one pump piston that defines a pump work chamber. The pump piston is driven in a reciprocating motion, counter to the force of a restoring spring, by a drive shaft that is driven to rotate. The pump piston is braced at least indirectly on the drive shaft via a sleevelike tappet, and the tappet is guided in a bore in a housing of the high-pressure pump in the direction of motion of the pump piston. The restoring spring is braced at least indirectly on the pump piston and on the tappet. The restoring spring is intended to keep both the pump piston in contact with the tappet and the tappet in contact with the drive shaft. The tappet must take on both the function of transverse force absorption for the pump piston and the function of bracing on the drive shaft. Particularly when the bracing of tappet on the drive shaft is effected via a roller supported in the drive shaft, the result is a complex embodiment of the tappet, which may for instance be embodied as a cast or forged part and has a high weight. The attempt is therefore made to split up the functions of guidance and transverse force absorption for the pump piston and the bracing on the drive shaft to separate components. The restoring spring is intended to act on all of the components, but this is made more difficult because of the production tolerances of the components. If there is play between the components, this play is overcome, particularly in the regions of the reversal of motion of the pump piston, or in other words at its inner and outer dead centers; as a result, the components hit one another, causing increased wear of these components.